Up to the highest peak!

In the early hours of this morning, the beam energy was ramped up to 3.5 TeV, a new world record and the highest energy for this year’s run. Now operators will prepare the machine to make high-energy collisions later this month.

CERN Operations Group leader Mike Lamont (foreground) and LHC engineer in charge Alick Macpherson in the CERN Control Centre early this morning.

At 5:23 this morning, Friday 19 March, the energy of both beams in the LHC was ramped up to 3.5 TeV, a new world record. During the night, operators had tested the performance of the whole machine with two so-called ‘dry runs’, that is, without beams. Given the good overall response, beams were injected at around 3:00 a.m. and stabilized soon after. The ramp started at around 4:10 and lasted about one hour.

Over the last couple of weeks, operation of the LHC at 450 GeV has become routinely reproducible. The operators were able to test and optimize the beam orbit, the beam collimation, the injection and extraction phases as well as the associated protection system. On 12 March, both beams were ramped up to 1.18 TeV. The overall response from the machine was very positive.

The first part of this week saw a technical stop, during which the magnet and magnet protection experts continued their campaign to commission the machine to 6 kAmps – the current needed to operate at 3.5 TeV per beam. Tests are still ongoing to fully understand the electrical behaviour of the dipole circuits with currents higher than 2 kAmps, which has an impact on the quench protection system (see box) and on the procedure for ramping the beam energy to 3.5 TeV (6kAmps).

While the experts are working to fully understand the circuit performance (for details, watch the embedded video interview with Andrzej Siemko, Group Leader of the LHC machine protection), the operators will continue ramping the beam energy and prepare for high-energy collisions later this month.

Watch the videos:

The LHC Quench Protection System

The LHC quench protection system (QPS) has the crucial role of providing an early warning for any part of the superconducting coils and busbars that develops high resistance, as well as triggering the switch-off of the machine. Thousands of detectors are installed all along the machine and hundreds of crates, installed along the ring, house the detector boards.

One of the major consolidation activities for the LHC in 2009 was the addition of about 6000 new detectors to the quench protection system. The campaign was designed to sensibly improve the quality of the monitoring and the effectiveness of the response. Some non-conformities relating to the QPS appeared a few times during the machine commissioning and were successfully fixed by the experts.

For further information about the LHC quench protection system, please read a previous Bulletin article and watch the video.